Driving method, touch sensing circuit, display panel, and touch display device

ABSTRACT

A touch sensing circuit can include a plurality of touch electrodes; and a touch circuit configured to supply at least one touch driving signal to at least one of the plurality of touch electrodes, in which the at least one touch driving signal includes a first touch driving signal and a second touch driving signal, and the first touch driving signal has a first frequency in a first touch period included in a first frame, and the second touch driving signal has a second frequency different from the first frequency in a second touch period included in a second frame subsequent to the first frame.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of U.S. patent application Ser. No.16/780,641, filed on Feb. 3, 2020 (now U.S. Pat. No. 11,126,302 issuedon Sep. 21, 2021), which is a Continuation of U.S. patent applicationSer. No. 15/387,222, filed on Dec. 21, 2016 (now U.S. Pat. No.10,572,055 issued on Feb. 25, 2020), which claims priority benefit fromKorean Patent Application No. 10-2016-0083114, filed in the Republic ofKorea on Jun. 30, 2016, all of these applications are herebyincorporated by reference for all purposes as if fully set forth herein.

BACKGROUND Technical Field

The embodiments of the disclosure relate to a driving method, a touchsensing circuit, a display panel, and a touch display device.

Description of the Related Art

With advancement of information-oriented societies, various kinds ofdemands for display devices for displaying images have increased, andvarious types of display devices have been used, such as a liquidcrystal display device (LCD), a plasma display panel (PDP), and anorganic light-emitting display device (OLED). Among such displaydevices, touch display devices that can provide a touch-based inputsystem enabling a user to easily and intuitively input information orcommands in addition to a normal input system using buttons, keyboards,mouse, and the like are known.

In order to provide such a touch-based input system, such touch displaydevices need to detect a user's touch and accurately detect a touchedcoordinate (a touch position). For this purpose, a capacitive touchsystem that detects a touch and a touch coordinate on the basis of avariation in capacitance between plural touch electrodes disposed astouch sensors in a touch panel (a touch screen panel) or capacitancebetween the touch electrodes and a point such as a finger using thetouch electrodes has been widely employed.

On the other hand, an electronic device such as a touch display devicehaving a touch sensing function has to satisfy a condition that anelectromagnetic interference (EMI) level is equal to or less than apredetermined level. However, the touch display devices have a problemin that the EMI level is considerably high due to a touch driving signalfor sensing a touch.

Particularly, when a touch driving signal applied to the touchelectrodes to sense a touch is a pulse type (rectangular wave) signalhaving a predetermined frequency, an influence of the EMI may furtherincrease. There is also a problem in that the EMI deteriorates systemstability of a touch display device, deteriorates touch sensingperformance by affecting a sensing voltage at the time of sensing atouch or the like, or deteriorates display performance by affectingvoltages required for displaying an image.

SUMMARY

An object of the present disclosure is to provide a driving method, atouch sensing circuit, a display panel, and a touch display device thatcan prevent electromagnetic interference (EMI). Another object of thepresent disclosure is to provide a driving method, a touch sensingcircuit, a display panel, and a touch display device that can preventEMI in a touch section and prevent unnecessary parasitic capacitancefrom being generated. Still another object of the present disclosure isto provide a driving method, a touch sensing circuit, a display panel,and a touch display device that can perform touch driving using amulti-frequency driving method capable of preventing EMI.

According to an aspect of the present disclosure, there is provided atouch display device having a display panel in which a plurality of datalines and a plurality of gate lines are arranged and a plurality of subpixels defined by the plurality of data lines and the plurality of gatelines are arranged, and having a display mode for displaying an imageand a touch mode for sensing a touch. The touch display device includes:a plurality of touch electrodes that are arranged outside or inside thedisplay panel; and a touch sensing circuit that outputs a touch drivingsignal of a pulse type for driving at least one of the plurality oftouch electrodes and senses a touch or a touch position in one or moretouch sections for the touch mode. Each touch section for the touch modeincludes k or more unit touch sections where k is a natural number equalto or greater than 2. The touch driving signal output in each of the kor more unit touch sections has a constant frequency. The frequency ofthe touch driving signal output in at least one unit touch section ofthe k or more unit touch sections is different from the frequency of thetouch driving signal output in another unit touch section.

According to another aspect of the present disclosure, there is provideda driving method of a touch display device having a display panel inwhich a plurality of data lines and a plurality of gate lines arearranged and a plurality of sub pixels defined by the plurality of datalines and the plurality of gate lines are arranged, the touch displaydevice having a display mode for displaying an image and a touch modefor sensing a touch. The driving method includes: driving data lines andgate lines in a display section for the display mode; and outputting atouch driving signal of a pulse type for driving at least one of aplurality of touch electrodes, which are arranged outside or inside thedisplay panel, in a touch section for the touch mode. Each touch sectionincludes k (where k is a natural number equal to or greater than 2) ormore unit touch sections. The touch driving signal output in each of thek or more unit touch sections has a constant frequency. The frequency ofthe touch driving signal output in at least one unit touch section ofthe k or more unit touch sections is different from the frequency of thetouch driving signal output in another unit touch section.

According to still another aspect of the present disclosure, there isprovided a touch sensing circuit that is included in a touch displaydevice having a display mode for displaying an image and a touch modefor sensing a touch. The touch sensing circuit includes: a drivingcircuit that outputs a touch driving signal of a pulse type for drivingat least one of a plurality of touch electrodes in one or more touchsections for the touch mode; and a sensing circuit that detects acapacitance variation in each of the plurality of touch electrodes andsenses a touch or a touch position. Each of the one or more touchsections for the touch mode includes k or more unit touch sections,where k is a natural number equal to or greater than 2. The touchdriving signal output in each of the k or more unit touch sections has aconstant frequency. The frequency of the touch driving signal output inat least one unit touch section of the k or more unit touch sections isdifferent from the frequency of the touch driving signal output inanother unit touch section.

According to still another aspect of the present disclosure, there isprovided a touch sensing circuit that is included in a touch displaydevice having a display mode for displaying an image and a touch modefor sensing a touch. The touch sensing circuit includes: a signal outputunit that outputs a touch driving signal of a pulse type for driving atleast one of a plurality of touch electrodes for sensing a touch in oneor more touch sections for the touch mode; and a signal detecting unitthat detects a signal for sensing a touch from the touch electrodesupplied with the touch driving signal. Each of the one or more touchsections for the touch mode includes k or more unit touch sections,where k is a natural number equal to or greater than 2. The touchdriving signal output in each of the k or more unit touch sections has aconstant frequency. The frequency of the touch driving signal output inat least one unit touch section of the k or more unit touch sections isdifferent from the frequency of the touch driving signal output inanother unit touch section.

According to still another aspect of the present disclosure, there isprovided a display panel including: a plurality of data lines that aresupplied with data voltages corresponding to an image signal in adisplay section; a plurality of gate lines that are supplied with a scansignal in the display section; and a plurality of touch electrodes thatare supplied with a touch driving signal of a pulse type in one or moretouch sections. Each of the one or more touch sections includes k ormore unit touch sections, where k is a natural number equal to orgreater than 2. The touch driving signal output in each of the k or moreunit touch sections has a constant frequency. The frequency of the touchdriving signal output in at least one unit touch section of the k ormore unit touch sections may be different from the frequency of thetouch driving signal output in another unit touch section.

According to exemplary embodiments of the present disclosure, it ispossible to provide a driving method, a touch sensing circuit, a displaypanel, and a touch display device that can prevent electromagneticinterference (EMI). Accordingly, it is possible to prevent deteriorationin system stability, display performance, and touch sensing performancedue to EMI.

According to exemplary embodiments of the present disclosure, it ispossible to provide a driving method, a touch sensing circuit, a displaypanel, and a touch display device that can prevent EMI in a touchsection and prevent unnecessary parasitic capacitance from beinggenerated. According to exemplary embodiments of the present disclosure,it is possible to provide a driving method, a touch sensing circuit, adisplay panel, and a touch display device that can perform touch drivingusing a multi-frequency driving method (a frequency varying method)capable of preventing EMI.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features and other advantages of thepresent disclosure will be more clearly understood from the followingdetailed description taken in conjunction with the accompanyingdrawings, in which:

FIG. 1 is a diagram schematically illustrating a system configuration ofa touch display device according to an embodiment of the presentdisclosure;

FIG. 2 is a diagram illustrating a signal which is applied to a touchelectrode in a display section and a touch section in the touch displaydevice according to an embodiment of the present disclosure;

FIG. 3 is a diagram illustrating display sections and touch sectionsbased on a V-sensing method in the touch display device according to anembodiment of the present disclosure;

FIG. 4 is a diagram illustrating display sections and touch sectionsbased on an H-sensing method in the touch display device according to anembodiment of the present disclosure;

FIG. 5 is a diagram illustrating parasitic capacitance components whichare generated in the touch display device according to an embodiment ofthe present disclosure;

FIG. 6 is a diagram illustrating load-free driving in the touch displaydevice according to an embodiment of the present disclosure;

FIG. 7 is a diagram illustrating an electromagnetic interference (EMI)measurement result in touch sections in the touch display deviceaccording to an embodiment of the present disclosure;

FIG. 8 is a diagram illustrating waveform modulation driving for EMIimprovement in the touch display device according to an embodiment ofthe present disclosure;

FIG. 9 is a diagram illustrating signal characteristics of touch drivingsignals in a unit touch section in which a touch driving signal of asingle frequency is output for the purpose of explaining multi-frequencydriving characteristics in the touch display device according to anembodiment of the present disclosure;

FIG. 10 is a diagram illustrating an example in which the touch displaydevice according to an embodiment of the present disclosure modulates afrequency of a touch driving signal to perform multi-frequency drivingfor each touch section;

FIG. 11 is a diagram illustrating a frequency modulating method based onthe number of pulses in unit touch sections when the touch displaydevice according to an embodiment of the present disclosure modulates afrequency of a touch driving signal to perform multi-frequency drivingfor each touch section;

FIG. 12 is a diagram illustrating a frequency modulating method based onsection lengths of unit touch sections when the touch display deviceaccording to an embodiment of the present disclosure modulates afrequency of a touch driving signal to perform multi-frequency drivingfor each touch section;

FIG. 13 is a diagram illustrating load-free driving when the touchdisplay device according to an embodiment of the present disclosuremodulates a frequency of a touch driving signal to performmulti-frequency driving for each touch section;

FIG. 14 is a diagram illustrating an example in which the touch displaydevice according to an embodiment of the present disclosure modulates afrequency of a touch driving signal to perform multi-frequency drivingin each touch section;

FIG. 15 is a diagram illustrating a frequency modulating method based onthe number of pulses in unit touch sections when the touch displaydevice according to an embodiment of the present disclosure modulates afrequency of a touch driving signal to perform multi-frequency drivingin each touch section;

FIG. 16 is a diagram illustrating a frequency modulating method based onsection lengths of unit touch sections when the touch display deviceaccording to an embodiment of the present disclosure modulates afrequency of a touch driving signal to perform multi-frequency drivingin each touch section;

FIG. 17 is a diagram illustrating load-free driving when the touchdisplay device according to an embodiment of the present disclosuremodulates a frequency of a touch driving signal to performmulti-frequency driving in each touch section;

FIGS. 18 and 19 are diagrams illustrating an example in which the touchdisplay device according to embodiments of the present disclosureperforms multi-frequency driving using a V-sensing method;

FIGS. 20 and 21 are diagrams illustrating an example in which the touchdisplay device according to embodiments of the present disclosureperforms multi-frequency driving using an H-sensing method;

FIGS. 22 and 23 are diagrams illustrating touch driving based onmultiple frequencies in the touch display device according toembodiments of the present disclosure;

FIG. 24 is a diagram illustrating touch driving based on multiplefrequencies using a V-sensing method in the touch display deviceaccording to an embodiment of the present disclosure;

FIGS. 25 and 26 are diagrams illustrating touch driving based onmultiple frequencies using an H-sensing method in the touch displaydevice according to embodiments of the present disclosure;

FIG. 27 is a diagram illustrating a frequency modulating method fortouch driving based on multiple frequencies in the touch display deviceaccording to an embodiment of the present disclosure;

FIG. 28 is a diagram illustrating another frequency modulating methodfor touch driving based on multiple frequencies in the touch displaydevice according to an embodiment of the present disclosure;

FIG. 29 is a diagram illustrating frequency modulation characteristicsfor touch driving based on multiple frequencies in the touch displaydevice according to an embodiment of the present disclosure;

FIG. 30 is a flowchart illustrating a driving method of the touchdisplay device according to an embodiment of the present disclosure;

FIGS. 31 and 32 are diagrams illustrating a touch sensing circuit of thetouch display device according to embodiments of the present disclosure;

FIG. 33 is a diagram illustrating a driving circuit of the touch sensingcircuit of the touch display device according to an embodiment of thepresent disclosure; and

FIG. 34 is a diagram illustrating an EMI suppression effect in the touchdisplay device according to an embodiment of the present disclosure.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Hereinafter, some embodiments of the disclosure will be described indetail with reference to the accompanying illustrative drawings. Indenoting elements of the drawings by reference numerals, the sameelements will be referenced by the same reference numerals although theelements are illustrated in different drawings. In the followingdescription of the disclosure, detailed description of known functionsand configurations incorporated herein will be omitted when it may makethe subject matter of the disclosure rather unclear.

Terms, such as first, second, A, B, (a), or (b) may be used herein todescribe elements of the disclosure. Each of the terms is not used todefine essence, order, sequence, or number of an element, but is usedmerely to distinguish the corresponding element from another element.When it is mentioned that an element is “connected” or “coupled” toanother element, it should be interpreted that another element may be“interposed” between the elements or the elements may be “connected” or“coupled” to each other via another element as well as that one elementis directly connected or coupled to another element.

FIG. 1 is a diagram schematically illustrating a system configuration ofa touch display device 100 according to an embodiment of the presentdisclosure. FIG. 2 is a diagram illustrating a signal which is appliedto a touch electrode TE in display sections DS and touch sections TS inthe touch display device 100 according to an embodiment of the presentdisclosure.

The touch display device 100 according to the embodiment of the presentdisclosure includes a display panel 110 in which plural data lines DLsupplied with data voltages corresponding to image signals and pluralgate lines GL supplied with a scan signal are arranged and plural subpixels SP defined by the data lines DL and the gate lines GL arearranged. The touch display device 100 according to the embodiment ofthe present disclosure has two operation modes including a display modefor displaying an image and a touch mode for sensing a touch.

In a display section for the display mode, data voltages correspondingto image signals are supplied to the data lines and a scan signal issequentially supplied to the gate lines. The touch display device 100according to the embodiment of the present disclosure includes a datadriving circuit and a gate driving circuit for operation in the displaymode. In a display section DS in which the touch display device 100according to the embodiment of the present disclosure operates in thedisplay mode, the data driving circuit drives the data lines DL and thegate driving circuit drives the gate lines GL.

The touch display device 100 according to the embodiment of the presentdisclosure includes a touch sensing circuit 120 for operation in thetouch mode. In a touch section TS in which the touch display device 100according to the exemplary embodiments operates in the touch mode, thetouch sensing circuit 120 outputs a touch driving signal TDS of a pulsetype (for example, a pulse width modulation (PWM) type) for driving atleast one of plural touch electrodes TE electrically connected theretovia signal lines SL to sense a touch or a touch position.

As a touch electrode driving method, the touch sensing circuit 120 maysequentially drive at least one of the touch electrodes (a sequentialdriving method) or may simultaneously drive all the touch electrodes TE(a simultaneous driving method). When the touch electrode driving methodis the sequentially driving method or the simultaneous driving method,the touch sensing circuit 120 sequentially senses a touch and a touchposition using a signal received from at least one of the touchelectrodes TE as a sensing process of sensing (detecting) a touch and/ora touch position.

On the other hand, the touch sensing circuit 120 may detect acapacitance variation and sense a touch and/or a touch position on thebasis of the detected capacitance variation. That is, the touch displaydevice 100 according to the embodiment of the present disclosure cansense a touch using a capacitance-based touch sensing method. Thecapacitance-based touch sensing method includes a self-capacitance-basedtouch sensing method of detecting a capacitance variation between apointer such as a finger or a pen and the touch electrode TE to sense atouch and a mutual-capacitance-based touch sensing method of detecting acapacitance variation between two types of touch sensors to sense atouch. The mutual-capacitance-based touch sensing method is a method ofdetecting a capacitance variation between two types of touch sensors (adriving electrode and a receiving electrode) to sense a touch using adriving electrode (which is also referred to as a Tx electrode) suppliedwith the touch driving signal TDS and a receiving electrode (which isalso referred to as an Rx electrode) corresponding to the drivingelectrode. In the mutual-capacitance-based touch sensing method, thedriving electrode (Tx electrode) supplied with the touch driving signalTDS among the two types of touch sensors corresponds to the touchelectrode TE in this specification.

The self-capacitance-based touch sensing method is a method of supplyinga touch driving signal to the touch electrode TE and detecting a signalfrom the touch electrode TE supplied with the touch driving signal todetect the capacitance variation. The touch electrode TE correspondingto one type of touch sensor functions as the driving electrode and thereceiving electrode which are used in the mutual-capacitance-based touchsensing method. The touch display device 100 according to the embodimentof the present disclosure may perform touch driving and touch sensingusing the self-capacitance-based touch sensing method or may perform thetouch driving and the touch sensing using the mutual-capacitance-basedtouch sensing method. In the following description, for the purpose ofconvenience of explanation, it is assumed that the touch driving and thetouch sensing are performed using the self-capacitance-based touchsensing method.

Accordingly, the touch sensing circuit 120 can drive at least one of thetouch electrodes TE and detect a capacitance variation of the touchelectrodes TE on the basis of a signal received from the touchelectrodes to sense a touch and/or a touch position. On the other hand,the touch electrodes TE functioning as touch sensors may be arranged ina touch panel which is present outside the display panel 110 or may bedisposed inside the display panel 110. In this way, when the touchelectrodes TE are disposed in the display panel 110, the touchelectrodes TE can be arranged in an in-cell type or an on-cell type.

On the other hand, when the touch display device 100 according to theembodiment of the present disclosure operates in the display mode, acommon voltage Vcom can be applied to all the sub pixels. For thispurpose, a common voltage electrode supplied with the common voltageVcom is disposed in the display panel 110. When the touch electrodes TEare disposed inside the display panel 110, the touch electrodes TE canfunction as a common voltage electrode which is supplied with the commonvoltage Vcom in the display sections DS. When the touch display device100 is a liquid crystal display device, the common voltage Vcom is usedto cause a potential difference from a pixel voltage (corresponding to adata voltage) of each sub pixel and to express gray scales of the subpixel.

As described above, when the touch electrodes TE are used as the commonvoltage electrode, the touch electrodes TE functions as the commonvoltage electrode in the display section DS and functions as the touchsensor in the touch section TS in the touch display device 100 accordingto the embodiment of the present disclosure as illustrated in FIG. 2 .

Referring to FIG. 2 , the display section DS and the touch section TSare defined by temporally dividing one frame. Depending on the methodsof temporally dividing one frame into the display sections DS and thetouch sections TS, the touch sensing method can be classified into aV-sensing method illustrated in FIG. 3 and an H-sensing methodillustrated in FIG. 4 .

FIG. 3 is a diagram illustrating a display section DS and a touchsection TS based on the V-sensing method in the touch display device 100according to an embodiment of the present disclosure. FIG. 4 is adiagram illustrating display sections DS and touch sections DS based onthe H-sensing method in the touch display device 100 according to anembodiment of the present disclosure.

Referring to FIG. 3 , in the V-sensing method, one frame is temporallydivided into one display section DS and one or more touch sections TS.In the one display section DS, the touch display device 100 performsdisplay driving for one frame. In the one or more touch sections (TS),the touch display device 100 senses a touch or a touch position for oneframe.

Referring to FIG. 4 , in the H-sensing method, one frame is temporallydivided into two or more display sections DS and one or more touchsections TS. In the two or more display sections DS, the touch displaydevice 100 performs display driving for one frame. In the two or moretouch sections TS, the touch display device 100 senses a touch or atouch position for one frame.

Referring to FIGS. 3 and 4 , the display section DS and the touchsection TS can be defined by a synchronization signal SYNC. Thesynchronization signal SYNC may be generated by a control element suchas a timing controller and be transmitted to a circuit for the displaydriving (for example, the data driving circuit and the gate drivingcircuit) and a circuit for the touch driving (for example, the touchsensing circuit 120). Referring to FIGS. 3 and 4 , in thesynchronization signal SYNC, a high-level section (or a low-levelsection) corresponds to the display section DS, and the low-levelsection (or the high-level section) corresponds to the touch section TS.

FIG. 5 is a diagram illustrating parasitic capacitance components Cp1,Cp2, and Cp3 generated in the touch display device 100 according to anembodiment of the present disclosure. Referring to FIG. 5 , when a touchdriving signal TDS is supplied to one or more touch electrodes TEs, thetouch electrodes TEs supplied with the touch driving signal TDS can formthe parasitic capacitance component Cp1 in cooperation with the dataline DL, forms the parasitic capacitance component Cp2 in cooperationwith the gate line GL, and form the parasitic capacitance component Cp3in cooperation with another touch electrode TEo not supplied with thetouch driving signal TDS.

In this way, the parasitic capacitance components Cp1, Cp2, and Cp3generated in the touch section TS may function as a load in the touchsensing to decrease sensing accuracy. Accordingly, the touch displaydevice 100 according to the embodiments of the present disclosure canperform load-free driving capable of preventing or reducing generationof the parasitic capacitance components Cp1, Cp2, and Cp3 functioning asa load at the time of sensing a touch when at least one of the touchelectrodes TE is driven in the touch section TS.

FIG. 6 is a diagram illustrating the load-free driving of the touchdisplay device 100 according to an embodiment of the present disclosure.Referring to FIG. 6 , the touch display device 100 according to theembodiment of the present disclosure can supply a load-free drivingsignal D_LFDS to all or a part of the data lines DL when a touch drivingsignal TDS is supplied to one or more touch electrodes TEs in the touchsection TS.

Some data lines DL supplied with the load-free driving signal D_LFDSamong the data lines DL may be data lines arranged at positionscorresponding to the touch electrodes TEs supplied with the touchdriving signal TDS. The load-free driving signal D_LFDS supplied to allor some of the data lines DL may be a touch driving signal TDS or asignal corresponding to the touch driving signal TDS. When the load-freedriving signal D_LFDS corresponds to the touch driving signal TDS, theload-free driving signal D_LFDS may have the same frequency as the touchdriving signal TDS, the same phase as the touch driving signal TDS, andthe same amplitude as the touch driving signal TDS.

Accordingly, a potential difference is not generated between the touchelectrode TEs supplied with the touch driving signal TDS and the dataline DL supplied with the load-free driving signal D_LFDS and it is thuspossible to prevent the parasitic capacitance Cp1 from being formedbetween the touch electrode TEs supplied with the touch driving signalTDS and the data line DL supplied with the load-free driving signalD_LFDS.

Referring to FIG. 6 , the touch display device 100 according to theembodiment of the present disclosure can supply a load-free drivingsignal G_LFDS to all or some of the gate lines GL when a touch drivingsignal TDS is supplied to one or more touch electrodes TEs in the touchsection TS. Some gate lines GL supplied with the load-free drivingsignal D_LFDS among the gate lines GL may be gate lines arranged atpositions corresponding to the touch electrodes TEs supplied with thetouch driving signal TDS.

The load-free driving signal G_LFDS supplied to all or some of the gatelines GL may be a touch driving signal TDS or a signal corresponding tothe touch driving signal TDS. When the load-free driving signal G_LFDScorresponds to the touch driving signal TDS, the load-free drivingsignal G_LFDS may have the same frequency as the touch driving signalTDS, the same phase as the touch driving signal TDS, and the sameamplitude as the touch driving signal TDS. Accordingly, a potentialdifference is not generated between the touch electrode TEs suppliedwith the touch driving signal TDS and the gate line GL supplied with theload-free driving signal G_LFDS and it is thus possible to prevent theparasitic capacitance Cp2 from being formed between the touch electrodeTEs supplied with the touch driving signal TDS and the gate line GLsupplied with the load-free driving signal G_LFDS.

Referring to FIG. 6 , the touch display device 100 according to theembodiment of the present disclosure can supply a load-free drivingsignal T_LFDS to another touch electrode TEo not supplied with a touchdriving signal TDS when the touch driving signal TDS is supplied to oneor more touch electrodes TEs in the touch section TS. The another touchelectrode TEo supplied with the load-free driving signal T_LFDS amongthe touch electrodes TE may be a touch electrode TE arranged adjacent tothe touch electrode TEs supplied with the touch driving signal TDS orall the other touch electrodes TE. The load-free driving signal T_LFDSsupplied to another touch electrode TEo may be a touch driving signalTDS or a signal corresponding to the touch driving signal TDS.

When the load-free driving signal T_LFDS corresponds to the touchdriving signal TDS, the load-free driving signal T_LFDS may have thesame frequency as the touch driving signal TDS, the same phase as thetouch driving signal TDS, and the same amplitude as the touch drivingsignal TDS. Accordingly, a potential difference is not generated betweenthe touch electrode TEs supplied with the touch driving signal TDS andthe another touch electrode supplied with the load-free driving signalT_LFDS and it is thus possible to prevent the parasitic capacitance Cp3from being formed between the touch electrode TEs supplied with thetouch driving signal TDS and the another touch electrode TEo suppliedwith the load-free driving signal T_LFDS.

In the above-mentioned load-free driving, the load-free driving signal(at least one of D_LFDS, G_LFDS, and T_LFDS) supplied to at least one ofthe data line DL, the gate line GL, and the touch electrode TEo may bethe same signal as the touch driving signal TDS or may be a signaldifferent from or similar to the touch driving signal TDS as long asparasitic capacitance can be removed. Even when the touch sensingcircuit 120 outputs a load-free driving signal completely equal to thetouch driving signal TDS, the frequency, phase, voltage (amplitude), orsignal waveform (signal shape) of the load-free driving signal actuallysupplied to the data line DL, the gate line, or the touch electrode TEomay be different from the frequency, phase, voltage (amplitude), orsignal waveform (signal shape) of the touch driving signal TDS due topanel characteristics such as a load and a resistive-capacitive (RC)delay. In this way, a degree of difference between an output state andan actual supply state of the load-free driving signal may varydepending on a panel position (that is, a horizontal or verticalposition of the data line DL, the gate line GL, or the touch electrodeTEo supplied with the load-free driving signal).

In consideration of the fact that the output state and the actual supplystate of the load-free driving signal are different from each otherdepending on the panel characteristics and the supply position, thetouch driving signal or the load-free driving signal can be output afterthe output state thereof such that the actually supplied load-freedriving signal is equal to the actually supplied touch driving signal.Accordingly, the touch driving signal output from the touch sensingcircuit 120 and the load-free driving signal output from a load-freedriving circuit (for example, the touch sensing circuit, the datadriver, or the gate driver) may be equal to each other in all offrequency, phase, voltage (amplitude), and signal waveform (signalshape) or may be different from each other in at least one of frequency,phase, voltage (amplitude), and signal waveform (signal shape).

On the other hand, in the touch display device 100, when at least one ofthe touch electrodes TE is sequentially driven using a touch drivingsignal TDS of a pulse type having a single frequency (for example,several tens of KHz to several hundreds of KHz) in the touch section TS,electromagnetic interference (EMI) may occur in harmonic frequencycomponents due to a variation in voltage level of the touch drivingsignal TDS. Particularly, in the touch display device 100, when at leastone of the touch electrodes TE is sequentially driven using a touchdriving signal TDS of a pulse type (a rectangular wave) having a singlefrequency (for example, several tens of KHz to several hundreds of KHz)in the touch section TS and load-free driving of at least one of anothertouch electrode TEo, the data line DL, and the gate line GL is furtherperformed at this time, the EMI due to the touch driving signal TDS maybe intensified.

FIG. 7 is a diagram illustrating an EMI measurement result in a touchsection TS in the touch display device 100 according to an embodiment ofthe present disclosure. Referring to FIG. 7 , when the touch displaydevice 100 drives the touch electrodes TE using the touch driving signalTDS having a single frequency of 100 KHz, EMI may occur in an amplitudemodulation (AM) frequency region (for example, about 500 KHz to about1,605 KHz) due to the touch driving signal TDS.

FIG. 7 is a graph illustrating an upper-limit measured value 710 and anaverage measured value 720 of an EMI signal by frequencies which areobtained by measuring intensity of the EMI signal by frequencies. Fromthe measurement result, it can be confirmed that there is a point 712 atwhich the upper-limit measured value 710 of the EMI signal is greaterthan a reference upper limit value 711 which is a minimum upper limitvalue for satisfying an EMI condition in the AM frequency region. Fromthe measurement result, it can be confirmed that there is a point 722 atwhich the average measured value 720 of the EMI signal is greater than areference average value 721 which is a minimum upper limit value forsatisfying an EMI condition in the AM frequency region. That is, as themeasurement result, the upper-limit measured value 710 and the averagemeasured value 720 of the EMI signal may not satisfy the EMI conditionin the AM frequency region. Therefore, the touch display device 100according to the embodiment of the present disclosure can provide amulti-frequency driving method to suppress an EMI phenomenon due to thetouch driving signal TDS.

FIG. 8 is a diagram illustrating multi-frequency driving for EMIsuppression in the touch display device 100 according to an embodimentof the present disclosure. Referring to FIG. 8 , the touch sensingcircuit 120 of the touch display device 100 according to the embodimentof the present disclosure drives the touch electrodes TE using the touchdriving signal TDS having two or more frequencies while modulating thefrequency of the touch driving signal TDS.

In this touch driving method, a waveform having different amplitudelevels, that is, two or more amplitude levels or a trapezoidal waveformor a triangular (sawtooth-shaped) waveform having amplitude varying witha predetermined gradient may be used as a waveform of the first touchdriving signal TDS for driving the touch electrodes TE. According to themulti-frequency driving, the frequency of the touch driving signal TDSoutput from the touch sensing circuit 120 can be modulated.

As described above, according to the multi-frequency driving, an EMIcharge share phenomenon occurs with the modulation of the frequency ofthe touch driving signal TDS output from the touch sensing circuit 120,and an EMI phenomenon due to the touch driving signal TDS can besuppressed. In other words, the embodiment of the present disclosureprovide a touch sensing method, a touch sensing circuit 120, and a touchdisplay device 100 that can perform touch driving using amulti-frequency driving method to suppress EMI.

Here, the multi-frequency driving method is a touch driving method usingfrequency modulation of a touch driving signal and the frequencymodulation of a touch driving signal can be performed using a techniqueof adjusting a section length of a section (a unit touch section) inwhich a single frequency is used or a technique of adjusting the numberof pulses in a section in which a single frequency is used. Themulti-frequency driving of driving the touch electrodes TE using a touchdriving signal TDS having two or more frequencies based on the frequencymodulation of the touch driving signal TDS will be described below inmore detail.

FIG. 9 is a diagram illustrating signal characteristics of a touchdriving signal TDS in a unit touch section UTS in which the touchdriving signal TDS of a single frequency is output for the purpose ofexplaining multi-frequency driving characteristics in the touch displaydevice 100 according to an embodiment of the present disclosure. Whenthe touch electrodes TE are driven in a multi-frequency manner using atouch driving signal TDS having two or more frequencies based on thefrequency modulation of the touch driving signal TDS, a section in whichthe touch electrode TE is driven using the touch driving signal TDS of asingle frequency is present. This section is referred to as a unit touchsection UTS.

FIG. 9 illustrates the touch driving signal TDS in a unit touch sectionUTS. Referring to FIG. 9 , a unit touch section UTS has a predeterminedsection length T. A touch driving signal TDS of a pulse type output fromthe touch sensing circuit 120 in a unit touch section UTS has apredetermined frequency F and a number of pulses N. The section length Tof a unit touch section UTS is within the duration of one touch sectionTS.

The touch driving signal TDS of a pulse type output from the touchsensing circuit 120 in a unit touch section UTS has a duty ratio whichis defined by a length x of a high level section and a length y of a lowlevel section. The duty ratio of the touch driving signal TDS is x/(x+y)and may vary depending on the unit touch sections UTS or may be fixed inall the unit touch sections UTS.

For example, it is assumed that the duty ratio of the touch drivingsignal TDS is 50% which is fixed in all the unit touch sections UTS.That is, it is assumed that the length x of a high level section and thelength y of a low level section in the touch driving signal TDS areequal to each other.

FIGS. 10 to 13 are diagrams illustrating examples in which the touchdisplay device 100 according to embodiments of the present disclosuremodulates a frequency of a touch driving signal to performmulti-frequency driving for each touch section TS. FIGS. 14 to 17 arediagrams illustrating examples in which the touch display device 100according to an embodiment of the present disclosure modulates afrequency of a touch driving signal to perform multi-frequency drivingin each touch section TS. The multi-frequency driving method may varydepending on how the unit touch sections UTS are allocated.

As illustrated in FIGS. 10 to 13 , one touch section TS may correspondto one unit touch section UTS. In this way, when one touch section TSincludes a single unit touch section UTS, the frequency of the touchdriving signal TDS is constant in one touch section TS corresponding toone unit touch section UTS and the frequency of the touch driving signalTDS varies depending on the touch sections TS. Unlike this, asillustrated in FIGS. 14 to 17 , one touch section TS may correspond to k(where k is a natural number equal to or greater than 2) unit touchsections UTS. In this way, when one touch section TS includes two ormore unit touch sections UTS, the frequency of the touch driving signalTDS may vary depending on the unit touch sections UTS.

According to the multi-frequency driving, when there are two or moreunit touch sections UTS in which the touch driving signal TDS have thesame frequency, the frequencies of the touch driving signals TDS outputin the two or more unit touch sections UTS are different from eachother. The frequency of each of the touch driving signals TDS output inthe two or more unit touch sections UTS can be defined by the sectionlength T of the unit touch section UTS and the number of pulses N of thetouch driving signal TDS in the unit touch section UTS.

According to the first frequency modulation technique, the sectionlengths T of the two or more unit touch sections UTS may be equal toeach other and the numbers of pulses N of the touch driving signals TDSin the two or more unit touch sections UTS may be different from eachother. According to the second frequency modulation technique, thesection lengths T of the two or more unit touch sections UTS may bedifferent from each other and the numbers of pulses N of the touchdriving signals TDS in the two or more unit touch sections UTS may beequal to each other. The multi-frequency driving method depending on theallocation methods of the unit touch sections UTS will be describedbelow in more detail.

The multi-frequency driving method when one touch section TS includes asingle unit touch section UTS will be first described below withreference to FIGS. 10 to 13 . Referring to FIG. 10 , a first unit touchsection UTS1 in which a touch driving signal TDS1 of a first frequencyF1 is output and a second unit touch section UTS2 in which a touchdriving signal TDS2 of a second frequency F2 is output are present tocorrespond to a first touch section TS1 and a second touch section TS2.

The first frequency F1 of the touch driving signal TDS1 in the firstunit touch section UTS1 is different from the second frequency F2 of thetouch driving signal TDS2 in the second unit touch section UTS2. Thefirst frequency F1 of the touch driving signal TDS1 in the first unittouch section UTS1 can be defined by a section length T1 of the firstunit touch section UTS1 and the number of pulses N1 in the first unittouch section UTS1 as expressed by Expression 1.

$\begin{matrix}{{F\; 1} \propto \frac{N\; 1}{T\; 1}} & {{Expression}\mspace{14mu} 1}\end{matrix}$

The second frequency F2 of the touch driving signal TDS2 in the secondunit touch section UTS2 can be defined by a section length T2 of thesecond unit touch section UTS1 and the number of pulses N2 in the secondunit touch section UTS2 as expressed by Expression 2.

$\begin{matrix}{{F\; 2} \propto \frac{N\; 2}{T\; 2}} & {{Expression}\mspace{14mu} 2}\end{matrix}$

As described above, by adjusting the number of pulses N of the touchdriving signal TDS in each unit touch section UTS or the section lengthT of each unit touch section UTS, the frequency F of the touch drivingsignal TDS in each unit touch section UTS can be efficiently modulated.

As illustrated in FIG. 11 , by adjusting the number of pulses N of thetouch driving signal TDS in each unit touch section UTS, the frequency Fof the touch driving signal TDS can be modulated. According to thefrequency modulating method based on the number of pulses, the sectionlength T1 of the first unit touch section UTS1 and the section length T2of the second unit touch section UTS2 are equal to each other and thenumber of pulses N1 of the touch driving signal TDS1 in the first unittouch section UTS1 and the number of pulses N2 of the touch drivingsignal TDS2 in the second unit touch section UTS2 are different fromeach other.

Referring to FIG. 11 , by outputting the touch driving signal TDS2 withthe number of pulses N2 less than the number of pulses N1 of the touchdriving signal TDS1 in the first unit touch section UTS1 in the secondunit touch section UTS2 having the section length T2 equal to thesection length T1 of the first unit touch section UTS1, the secondfrequency F2 of the touch driving signal TDS2 in the second unit touchsection UTS2 can be made to be lower than the first frequency F1 of thetouch driving signal TDS1 in the first unit touch section UTS1. Asdescribed above, according to the frequency modulating method based onthe number of pulses, since the section lengths T of the unit touchsections UTS are equal to each other, the frequency components can betemporally evenly distributed and it is thus possible to obtain a betterEMI suppression effect due to the effective distribution of the EMIcomponents.

On the other hand, as illustrated in FIG. 12 , the frequency F of thetouch driving signal TDS can be modulated by adjusting the sectionlength T of each unit touch section UTS. According to the frequencymodulating method based on the section length, the number of pulses N1of the touch driving signal TDS1 in the first unit touch section UTS1and the number of pulses N2 of the touch driving signal TDS2 in thesecond unit touch section UTS2 are equal to each other, and the sectionlength T1 of the first unit touch section UTS1 and the section length T2of the second unit touch section UTS2 are different from each other.

Referring to FIG. 12 , by outputting the touch driving signal TDS2 withthe number of pulses N2 equal to the number of pulses N1 of the touchdriving signal TDS1 in the first unit touch section UTS1 in the secondunit touch section UTS2 having the section length T2 larger than thesection length T1 of the first unit touch section UTS1, the secondfrequency F2 of the touch driving signal TDS2 in the second unit touchsection UTS2 can be made to be lower than the first frequency F1 of thetouch driving signal TDS1 in the first unit touch section UTS1. Asdescribed above, according to the frequency modulating method based onthe section length, since the numbers of pulses N of the unit touchsections UTS are equal to each other, it is possible to easily generatepulses for the frequency modulation.

FIG. 13 is a diagram illustrating load-free driving (LFD) when the touchdisplay device 100 according to an embodiment of the present disclosuremodulates a frequency of a touch driving signal TDS to performmulti-frequency driving for each touch section TS. When the frequency ofthe touch driving signal TDS is modulated to perform multi-frequencydriving for each touch section TS, a load-free driving signal D_LFDS canbe supplied to all or a part of the data lines DL in a touch section inwhich a touch driving signal TDS is supplied to at least one of thetouch electrodes TE. The load-free driving signal D_LFDS supplied to allor a part of the data lines DL may be the touch driving signal TDS ormay be a signal corresponding to the touch driving signal TDS infrequency, phase, or amplitude. When the frequency of the touch drivingsignal TDS is changed from F1 to F2 by the multi-frequency driving, thefrequency of the load-free driving signal D_LFDS supplied to all or apart of the data lines DL can be changed from F1 to F2.

Referring to FIG. 13 , the frequency of a load-free driving signalD_LFDS1 output to the data lines DL in the first unit touch section UTS1is determined depending on the first frequency F1 of the touch drivingsignal TDS1 output in the first unit touch section UTS1, and thefrequency of a load-free driving signal D_LFDS2 output to the data linesDL in the second unit touch section UTS2 is determined depending on thesecond frequency F2 of a touch driving signal TDS2 output in the secondunit touch section UTS2. Accordingly, a potential difference is notgenerated between the touch electrode TE supplied with the touch drivingsignal TDS and the data line DL supplied with the load-free drivingsignal D_LFDS even when the multi-frequency driving is performed, and itis thus possible to prevent parasitic capacitance Cp1 from being formedbetween the touch electrode TEs supplied with the touch driving signalTDS and the data line DL supplied with the load-free driving signalD_LFDS.

When the frequency of the touch driving signal TDS is modulated toperform multi-frequency driving for each touch section TS, a load-freedriving signal G_LFDS can be supplied to all or a part of the gate linesGL in a touch section in which a touch driving signal TDS is supplied toat least one of the touch electrodes TE. The load-free driving signalG_LFDS supplied to all or a part of the gate lines GL may be the touchdriving signal TDS or may be a signal corresponding to the touch drivingsignal TDS in frequency, phase, or amplitude. When the frequency of thetouch driving signal TDS is changed from F1 to F2 by the multi-frequencydriving, the frequency of the load-free driving signal G_LFDS suppliedto all or a part of the gate lines GL can be changed from F1 to F2.

Referring to FIG. 13 , the frequency of a load-free driving signalG_LFDS1 output to the gate lines GL in the first unit touch section UTS1is determined depending on the first frequency F1 of the touch drivingsignal TDS1 output in the first unit touch section UTS1, and thefrequency of a load-free driving signal G_LFDS2 output to the gate linesGL in the second unit touch section UTS2 is determined depending on thesecond frequency F2 of a touch driving signal TDS2 output in the secondunit touch section UTS2. Accordingly, a potential difference is notgenerated between the touch electrode TEs supplied with the touchdriving signal TDS and the gate lines GL supplied with the load-freedriving signal G_LFDS even when the multi-frequency driving isperformed, and it is thus possible to prevent parasitic capacitance Cp2from being formed between the touch electrode TEs supplied with thetouch driving signal TDS and the gate lines GL supplied with theload-free driving signal G_LFDS.

When the frequency of the touch driving signal TDS is modulated toperform multi-frequency driving for each touch section TS, a load-freedriving signal T_LFDS can be supplied to all or a part of other touchelectrodes TE in a touch section in which a touch driving signal TDS issupplied to at least one of the touch electrodes TE. The load-freedriving signal T_LFDS supplied to all or a part of the other touchelectrodes TE may be the touch driving signal TDS or may be a signalcorresponding to the touch driving signal TDS in frequency, phase, oramplitude. When the frequency of the touch driving signal TDS is changedfrom F1 to F2 by the multi-frequency driving, the frequency of theload-free driving signal T_LFDS supplied to all or a part of the othertouch electrodes TE can be changed from F1 to F2.

Referring to FIG. 13 , the frequency of a load-free driving signalT_LFDS1 output to the other touch electrodes TE in the first unit touchsection UTS1 is determined depending on the first frequency F1 of thetouch driving signal TDS1 output in the first unit touch section UTS1,and the frequency of a load-free driving signal T_LFDS2 output to theother touch electrodes TE in the second unit touch section UTS2 isdetermined depending on the second frequency F2 of a touch drivingsignal TDS2 output in the second unit touch section UTS2. Accordingly, apotential difference is not generated between the touch electrode TEsupplied with the touch driving signal TDS and the other touchelectrodes TEo supplied with the load-free driving signal T_LFDS evenwhen the multi-frequency driving is performed, and it is thus possibleto prevent parasitic capacitance Cp3 from being formed between the touchelectrode TEs supplied with the touch driving signal TDS and the othertouch electrodes TEo supplied with the load-free driving signal T_LFDS.

The multi-frequency driving method when one touch section TS includestwo or more unit touch sections UTS will be described below withreference to FIGS. 14 to 17 . In the following description, it isassumed that one touch section TS includes three unit touch sectionsUTS1, UTS2, and UTS3. It is also assumed that a first frequency F1 of atouch driving signal TDS1 in a first unit touch section UTS1, a secondfrequency F2 of a touch driving signal TDS2 in a second unit touchsection UTS2, and a third frequency F3 of a touch driving signal TDS3 ina third unit touch section UTS3 are different from each other.

Referring to FIG. 14 , one touch section TS includes the first unittouch section UTS1 in which the touch driving signal TDS1 of the firstfrequency F1, the second unit touch section UTS2 in which the touchdriving signal TDS2 of the second frequency F2 is output, and the thirdunit touch section UTS3 in which the touch driving signal TDS3 of thethird frequency F3 is output. The first frequency F1 of the touchdriving signal TDS1 in the first unit touch section UTS1, the secondfrequency F2 of the touch driving signal TDS2 in the second unit touchsection UTS2, and the third frequency F3 of the touch driving signalTDS3 in the third unit touch section UTS3 are not all equal to eachother. That is, the first frequency F1, the second frequency F2, and thethird frequency F3 may be different from each other, or two (F1 and F2,F1 and F3, or F2 and F3) of the first frequency F1, the second frequencyF2, and the third frequency F3 may be equal to each other and the otherone (F3, F2, or F1) may be different therefrom.

The first frequency F1 of the touch driving signal TDS1 in the firstunit touch section UTS1 may be defined by a section length T1 of thefirst unit touch section UTS1 and the number of pulses N1 in the firstunit touch section UTS1. The second frequency F2 of the touch drivingsignal TDS2 in the second unit touch section UTS2 may be defined by asection length T2 of the second unit touch section UTS2 and the numberof pulses N2 in the second unit touch section UTS2. The third frequencyF3 of the touch driving signal TDS3 in the third unit touch section UTS3may be defined by a section length T3 of the third unit touch sectionUTS3 and the number of pulses N3 in the third unit touch section UTS3.As described above, it is possible to efficiently modulate the frequencyF of the touch driving signal TDS in each unit touch section UTS byadjusting the number of pulses N of the touch driving signal TDS in eachunit touch section UTS or the section length T of each unit touchsection UTS.

As illustrated in FIG. 15 , it is possible to modulate the frequency Fof the touch driving signal TDS by adjusting the number of pulses N ofthe touch driving signal TDS in each unit touch section UTS. In thefrequency modulating method based on the number of pulses, the sectionlength T1 of the first unit touch section UTS1, the section length T2 ofthe second unit touch section UTS2, and the section length T3 of thethird unit touch section UTS3 may be equal to each other. However, thenumber of pulses N1 of the touch driving signal TDS1 in the first unittouch section UTS1, the number of pulses N2 of the touch driving signalTDS2 in the second unit touch section UTS2, and the number of pulses N3of the touch driving signal TDS3 in the third unit touch section UTS3are not equal to each other. That is, all of N1, N2, and N3 may not beequal to each other, or two of N1, N2, and N3 may be equal to each otherand the other one may be different therefrom.

Referring to FIG. 15 , by outputting the touch driving signal TDS2 withthe number of pulses N2 smaller than the number of pulses N1 of thetouch driving signal TDS 1 in the first unit touch section UTS1 in thesecond unit touch section UTS2 having the same section length T2 as thesection length T1 of the first unit touch section UTS1, the secondfrequency F2 of the touch driving signal TDS2 in the second unit touchsection UTS2 can be made to be lower than the first frequency F1 of thetouch driving signal TDS1 in the first unit touch section UTS1. Byoutputting the touch driving signal TDS3 with the number of pulses N3smaller than the number of pulses N1 of the touch driving signal TDS1 inthe first unit touch section UTS1 and larger than the number of pulsesN2 of the touch driving signal TDS2 in the second unit touch sectionUTS2 in the third unit touch section UTS3 having the same section lengthT3 as the section length T2 of the second unit touch section UTS2, thethird frequency F3 of the touch driving signal TDS3 in the third unittouch section UTS3 can be made to be higher than the second frequency F2of the touch driving signal TDS2 in the second unit touch section UTS2and lower than the first frequency F1 of the touch driving signal TDS1in the first unit touch section UTS1. As described above, according tothe frequency modulating method based on the number of pulses, since thesection lengths T of the unit touch sections UTS are equal to eachother, the frequency components can be temporally evenly distributed andit is thus possible to obtain a better EMI suppression effect due to theeffective distribution of the EMI components.

On the other hand, as illustrated in FIG. 16 , the frequency F of thetouch driving signal TDS can be modulated by adjusting the sectionlength T of each unit touch section UTS. According to the frequencymodulating method based on the section length, the number of pulses N1of the touch driving signal TDS1 in the first unit touch section UTS1,the number of pulses N2 of the touch driving signal TDS2 in the secondunit touch section UTS2, and the number of pulses N3 of the touchdriving signal TDS3 in the third unit touch section UTS3 may be equal toeach other.

The section length T1 of the first unit touch section UTS1, the sectionlength T2 of the second unit touch section UTS2, and the section lengthT3 of the third unit touch section UTS3 may not be equal to each other.That is, T1, T2, and T3 may be different from each other, or two of T1,T2, and T3 may be equal to each other and the other one may be differenttherefrom.

Referring to FIG. 16 , by outputting the touch driving signal TDS2 withthe number of pulses N2 equal to the number of pulses N1 of the touchdriving signal TDS1 in the first unit touch section UTS1 in the secondunit touch section UTS2 having the section length T2 larger than thesection length T1 of the first unit touch section UTS1, the secondfrequency F2 of the touch driving signal TDS2 in the second unit touchsection UTS2 can be made to be lower than the first frequency F1 of thetouch driving signal TDS1 in the first unit touch section UTS1. Byoutputting the touch driving signal TDS3 with the number of pulses N3equal to the number of pulses N2 of the touch driving signal TDS2 in thesecond unit touch section UTS2 in the third unit touch section UTS3having the section length T3 smaller than the section length T2 of thesecond unit touch section UTS2 and larger than the section length T1 ofthe first unit touch section UTS1, the third frequency F3 of the touchdriving signal TDS3 in the third unit touch section UTS3 can be made tobe higher than the second frequency F2 of the touch driving signal TDS2in the second unit touch section UTS2 and lower than the first frequencyF1 of the touch driving signal TDS1 in the first unit touch sectionUTS1. As described above, according to the frequency modulating methodbased on the section length, since the numbers of pulses N of the unittouch sections UTS are equal to each other, it is possible to easilygenerate pulses for the frequency modulation.

FIG. 17 is a diagram illustrating load-free driving (LFD) when the touchdisplay device 100 according to an embodiment of the present disclosuremodulates a frequency of a touch driving signal TDS to performmulti-frequency driving in each touch section. When the frequencies ofthe touch driving signals TDS1, TDS2, and TDS3 are modulated to performthe multi-frequency driving for each unit touch section UTS1, UTS2, orUTS3 in the touch section TS, load-free driving signals D_LFDS1,D_LFDS2, and D_LFDS3 can be supplied to all or a part of the data linesDL in the touch section in which the touch driving signals TDS1, TDS2,and TDS3 are supplied to at least one of the touch electrodes TE. Theload-free driving signals D_LFDS1, D_LFDS2, and D_LFDS3 supplied to allor a part of the data lines DL may be the touch driving signals TDS1,TDS2, and TDS3 or may be signals corresponding to the touch drivingsignals TDS1, TDS2, and TDS3 in frequency and phase.

When the frequencies of the touch driving signals TDS1, TDS2, and TDS3are changed to F1, F2, and F3 by the multi-frequency driving, thefrequencies of the load-free driving signals D_LFDS1, D_LFDS2, andD_LFDS3 supplied to all or a part of the data lines DL can also bechanged to F1, F2, and F3. That is, when the frequencies of the touchdriving signals TDS1, TDS2, and TDS3 are changed with the change of theunit touch section, the frequencies of the load-free driving signalsD_LFDS1, D_LFDS2, and D_LFDS3 supplied to all or a part of the datalines DL can be changed in synchronization therewith.

Referring to FIG. 17 , the frequency of the load-free driving signalD_LFDS1 output to the data lines DL in the first unit touch section UTS1is determined depending on the first frequency F1 of the touch drivingsignal TDS1 output in the first unit touch section UTS1, the frequencyof the load-free driving signal D_LFDS2 output to the data lines DL inthe second unit touch section UTS2 is determined depending on the secondfrequency F2 of the touch driving signal TDS2 output in the second unittouch section UTS2, and the frequency of the load-free driving signalD_LFDS3 output to the data lines DL in the third unit touch section UTS3is determined depending on the third frequency F3 of the touch drivingsignal TDS3 output in the third unit touch section UTS3. Accordingly, apotential difference is not generated between the touch electrodes TEsupplied with the touch driving signals TDS1, TDS2, and TDS3 and thedata lines DL supplied with the load-free driving signals D_LFDS1,D_LFDS2, and D_LFDS3 even when the multi-frequency driving is performed,and it is thus possible to prevent parasitic capacitance Cp1 from beingformed between the touch electrodes TEs supplied with the touch drivingsignals TDS1, TDS2, TDS3 and the data lines DL supplied with theload-free driving signals D_LFDS1, D_LFDS2, and D_LFDS3.

When the frequencies of the touch driving signals TDS1, TDS2, and TDS3are modulated to perform the multi-frequency driving for each unit touchsection UTS1, UTS2, or UTS3 in the touch section TS, load-free drivingsignals G_LFDS1, G_LFDS2, and G_LFDS3 can be supplied to all or a partof the gate lines GL in the touch section in which the touch drivingsignals TDS1, TDS2, and TDS3 are supplied to at least one of the touchelectrodes TE. The load-free driving signals G_LFDS1, G_LFDS2, andG_LFDS3 supplied to all or a part of the gate lines GL may be the touchdriving signals TDS1, TDS2, and TDS3 or may be signals corresponding tothe touch driving signals TDS1, TDS2, and TDS3 in frequency and phase.

When the frequencies of the touch driving signals TDS1, TDS2, and TDS3are changed by the multi-frequency driving, the frequencies of theload-free driving signals G_LFDS1, G_LFDS2, and G_LFDS3 supplied to allor a part of the gate lines GL can also be changed. That is, when thefrequencies of the touch driving signals TDS1, TDS2, and TDS3 arechanged with the change of the unit touch section, the frequencies ofthe load-free driving signals G_LFDS1, G_LFDS2, and G_LFDS3 supplied toall or a part of the gate lines GL can be changed in synchronizationtherewith.

Referring to FIG. 17 , the frequency of the load-free driving signalG_LFDS1 output to the gate lines GL in the first unit touch section UTS1is determined depending on the first frequency F1 of the touch drivingsignal TD output in the first unit touch section UTS1, the frequency ofthe load-free driving signal G_LFDS2 output to the gate lines GL in thesecond unit touch section UTS2 is determined depending on the secondfrequency F2 of the touch driving signal TDS2 output in the second unittouch section UTS2, and the frequency of the load-free driving signalG_LFDS3 output to the gate lines GL in the third unit touch section UTS3is determined depending on the third frequency F3 of the touch drivingsignal TDS3 output in the third unit touch section UTS3. Accordingly, apotential difference is not generated between the touch electrodes TEsupplied with the touch driving signals TDS1, TDS2, and TDS3 and thegate lines GL supplied with the load-free driving signals G_LFDS1,G_LFDS2, and G_LFDS3 even when the multi-frequency driving is performed,and it is thus possible to prevent parasitic capacitance Cp2 from beingformed between the touch electrodes TEs supplied with the touch drivingsignals TDS1, TDS2, TDS3 and the gate lines GL supplied with theload-free driving signals G_LFDS1, G_LFDS2, and G_LFDS3.

When the frequencies of the touch driving signals TDS1, TDS2, and TDS3are modulated to perform the multi-frequency driving for each unit touchsection UTS1, UTS2, or UTS3 in the touch section TS, load-free drivingsignals T_LFDS1, T_LFDS2, and T_LFDS3 can be supplied to all or a partof the other touch electrodes TE in the touch section in which the touchdriving signals TDS1, TDS2, and TDS3 are supplied to at least one of thetouch electrodes TE. The load-free driving signals T_LFDS1, T_LFDS2, andT_LFDS3 supplied to all or a part of the other touch electrodes TE maybe the touch driving signals TDS1, TDS2, and TDS3 or may be signalscorresponding to the touch driving signals TDS1, TDS2, and TDS3 infrequency and phase. When the frequencies of the touch driving signalsTDS1, TDS2, and TDS3 are changed by the multi-frequency driving, thefrequencies of the load-free driving signals T_LFDS1, T_LFDS2, andT_LFDS3 supplied to all or a part of the other touch electrodes TE canalso be changed. That is, when the frequencies of the touch drivingsignals TDS1, TDS2, and TDS3 are changed with the change of the unittouch section, the frequencies of the load-free driving signals T_LFDS1,T_LFDS2, and T_LFDS3 supplied to all or a part of the other touchelectrodes TE can be changed in synchronization therewith.

Referring to FIG. 17 , the frequency of the load-free driving signalT_LFDS1 output to the other touch electrodes TE in the first unit touchsection UTS1 is determined depending on the first frequency F1 of thetouch driving signal TDS1 output in the first unit touch section UTS1,the frequency of the load-free driving signal T_LFDS2 output to theother touch electrodes TE in the second unit touch section UTS2 isdetermined depending on the second frequency F2 of the touch drivingsignal TDS2 output in the second unit touch section UTS2, and thefrequency of the load-free driving signal T_LFDS3 output to the othertouch electrodes TE in the third unit touch section UTS3 is determineddepending on the third frequency F3 of the touch driving signal TDS3output in the third unit touch section UTS3. Accordingly, a potentialdifference is not generated between the touch electrodes TE suppliedwith the touch driving signals TDS1, TDS2, and TDS3 and the other touchelectrodes TEo supplied with the load-free driving signals T_LFDS1,T_LFDS2, and T_LFDS3 even when the multi-frequency driving is performed,and it is thus possible to prevent parasitic capacitance Cp3 from beingformed between the touch electrodes TEs supplied with the touch drivingsignals TDS1, TDS2, TDS3 and the other touch electrodes TE supplied withthe load-free driving signals T_LFDS1, T_LFDS2, and T_LFDS3.

As described above, the display section DS for the display mode and thetouch section TS for the touch mode may be temporally separated fromeach other. On the other hand, the display mode and the touch mode maybe simultaneously carried out. In this way, when the display mode andthe touch mode are simultaneously carried out, the display section DSfor the display mode and the touch section TS for the touch mode maymatch each other. In this case, the section in which the display modeand the touch section are simultaneously carried out may be referred toas a display section DS or may be referred to as a touch section TS ormay be referred to as a common mode section or a simultaneously modesection.

In the section in which the display mode and the touch section aresimultaneously carried out, each touch electrode simultaneouslyfunctions as a touch sensor and a display driving electrode (forexample, a common electrode supplied with a common voltage). There maybe two or more unit touch sections UTS in which the touch drivingsignals TDS having the same frequency are output. The two or more unittouch sections UTS may be included in a single touch section TS or maybe distributed to different touch sections TS.

For example, as illustrated in FIG. 10 , the first unit touch sectionUTS1 and the second unit touch section UTS2 may be distributed todifferent touch sections TS1 and TS2. That is, the first unit touchsection UTS1 may be included in the first touch section TS1 and thesecond unit touch section UTS2 may be included in the second touchsection TS2. As illustrated in FIG. 14 , the first unit touch sectionUTS1 and the second unit touch section UTS2 may be included in a singletouch section TS.

As described above, by changing allocation of the unit touch sectionsUTS which are the section in which the touch electrodes TE are drivenusing the touch driving signal TDS of a single frequency, it is possibleto adjust a period in which the frequency of the touch driving signalTDS is modulated and a length (the section length of a unit touchsection UTS) of a section in which the frequency of the touch drivingsignal TDS is kept constant. Accordingly, it is possible to provideeffective multi-frequency driving in consideration of frequencymodulation performance or touch sensing performance.

The multi-frequency driving using the frequency modulation by touchsections which has been described with reference of FIGS. 10 to 13 canbe applied to the V-sensing method illustrated in FIG. 3 and theH-sensing method illustrated in FIG. 4 . The multi-frequency drivingusing the frequency modulation in a touch section which has beendescribed with reference of FIGS. 14 to 17 can be applied to theV-sensing method illustrated in FIG. 3 and the H-sensing methodillustrated in FIG. 4 .

FIG. 18 is a diagram illustrating an example in which the touch displaydevice 100 according to an embodiment of the present disclosure performsthe multi-frequency driving using the frequency modulation by touchsections (FIGS. 10 to 13 ) in the V-sensing method. FIG. 19 is a diagramillustrating an example in which the touch display device 100 accordingto an embodiment of the present disclosure performs the multi-frequencydriving using the frequency modulation in each touch section (FIGS. 14to 17 ) in the V-sensing method.

Referring to FIGS. 18 and 19 , when the touch driving and the touchsensing are performed using the V-sensing method, one frame section mayinclude one display section DS and one or more touch sections TS. TheV-sensing method is also referred to as V-blank driving because thetouch driving is performed in a section in which the display driving isnot performed. As illustrated in FIG. 18 , when one frame sectionincludes one touch section, that is, when the touch sensing circuit 120modulates the frequency by touch sections to perform the multi-frequencydriving in performing the touch driving and the touch sensing using theV-sensing method, two or more unit touch sections UTS1 and UTS2 may bedistributed to different touch sections TS1 and TS2.

As illustrated in FIG. 19 , when one frame section includes one touchsection, that is, when the touch sensing circuit 120 modulates thefrequency in each touch section to perform the multi-frequency drivingin performing the touch driving and the touch sensing using theV-sensing method, two or more unit touch sections UTS1, UTS2, and UTS3may be included in one touch section TS. In other words, one touchsection included in one frame section is divided into three unit touchsections UTS1, UTS2, and UTS3, the first unit touch section UTS1 inwhich the touch driving is performed using the touch driving signal TDS1of the first frequency F1, the second unit touch section UTS2 in whichthe touch driving is performed using the touch driving signal TDS2 ofthe second frequency F2, and the third unit touch section UTS3 in whichthe touch driving is performed using the touch driving signal TDS3 ofthe third frequency F3 may be present in one touch section TS. Throughthe multi-frequency driving, the touch display device 100 according tothe embodiment of the present disclosure can perform the touch drivingand the touch sensing using the V-sensing method in consideration ofdisplay performance and touch performance and can achieve EMIsuppression effect.

FIGS. 20 and 21 are diagrams illustrating an example in which the touchdisplay device 100 according to embodiments of the present disclosureperforms the multi-frequency driving using the H-sensing method.Referring to FIG. 20 , when the touch display device 100 according to anembodiment of the present disclosure performs the touch driving and thetouch sensing using the H-sensing method, one frame section includes twoor more display sections and two or more touch sections. At this time,when the frequency of the touch driving signal TDS is modulated by touchsections TS, two or more unit touch sections UTS1 and UTS2 can bedistributed to two or more touch sections TS1 and TS2. Through themulti-frequency driving, the touch display device 100 according to theembodiment of the present disclosure can perform the touch driving andthe touch sensing using the H-sensing method in consideration of displayperformance and touch performance and can achieve EMI suppressioneffect.

Referring to FIG. 21 , when the touch display device 100 according to anembodiment of the present disclosure performs the touch driving and thetouch sensing using the H-sensing method, one frame section includes twoor more display sections and two or more touch sections. At this time,when the frequency of the touch driving signal TDS is modulated in eachtouch section TS1, the two or more unit touch sections UTS1, UTS2, andUTS3 may be included in each touch section TS1. Through themulti-frequency driving, the touch display device 100 according to theembodiment of the present disclosure can perform the touch driving andthe touch sensing using the H-sensing method in consideration of displayperformance and touch performance and can further distribute the EMIphenomenon, thereby further suppressing the EMI.

Referring to FIGS. 19 and 21 , the two or more unit touch sections UTS1,UTS2, and UTS3 are included in one touch section, the sum (T1+T2+T3) ofthe section lengths of the two or more unit touch sections UTS1, UTS2,and UTS3 may be equal to or less than the section length of one touchsection TS.

As described above, the touch display device 100 according toembodiments of the present disclosure can satisfy conditions of desireddisplay performance and touch performance as a whole and can efficientlyprovide the multi-frequency driving for EMI suppression.

The method of performing the touch driving based on the above-mentionedmulti-frequency driving to sense a touch will be described below.Specific embodiments of the present disclosure of the touch drivingmethod based on the multiple frequencies will be described below in moredetail.

FIGS. 22 and 23 are diagrams illustrating the touch driving based onmultiple frequencies of the touch display device according toembodiments of the present disclosure. FIG. 22 illustrates one touchsection TS for the touch mode.

Referring to FIG. 22 , each touch section TS1 includes two or more unittouch sections UTSa, UTSb, and UTSc. Touch driving signals TDSa, TDSb,and TDSc output from the two or more unit touch sections UTSa, UTSb, andUTSc have constant frequencies Fa, Fb, and Fc. The frequency of thetouch driving signal output in at least one unit touch section of thetwo or more unit touch sections UTSa, UTSb, and UTSc may be differentfrom the frequencies of the touch driving signals output in the otherunit touch sections.

According to the touch driving based on multiple frequencies, at leastone of the frequencies Fa, Fb, and Fc of the touch driving signals TDSa,TDSb, and TDSc output from the touch sensing circuit 120 in one touchsection TS1 is modulated differently, the EMI phenomenon occurring inthe touch driving may be suppressed by the effective distribution of theEMI components. Each of the frequencies Fa, Fb, and Fc of the touchdriving signals TDSa, TDSb, and TDSc output in the two or more unittouch sections UTSa, UTSb, and UTSc can be defined by the section lengthof the corresponding unit touch section and the number of pulses of thetouch driving signal in the corresponding unit touch section.

As described above, the touch display device 100 according to theembodiments of the present disclosure provides two frequency modulationtechniques to make the frequency of the touch driving signal output inat least one unit touch section of the two or more unit touch sectionsUTSa, UTSb, and UTSc different from the frequencies of the touch drivingsignals output in the other unit touch sections. The two frequencymodulation techniques include a first technique of modulating thefrequency by adjusting the number of pulses of a touch driving signaland a second technique of modulating the frequency by adjusting asection length of a unit touch section.

According to the first frequency modulation technique, the sectionlengths Ta, Tb, and Tc of the two or more unit touch sections UTSa,UTSb, and UTSc may be equal to each other and the numbers of pulses Na,Nb, and Nc of the touch driving signals TDSa, TDSb, and TDSc in the twoor more unit touch sections UTSa, UTSb, and UTSc may be different fromeach other. According to the second frequency modulation technique, thesection lengths Ta, Tb, and Tc of the two or more unit touch sectionsUTSa, UTSb, and UTSc may be different from each other and the numbers ofpulses Na, Nb, and Nc of the touch driving signals TDSa, TDSb, and TDScin the two or more unit touch sections UTSa, UTSb, and UTSc may be equalto each other. The sum of the section lengths Ta, Tb, and Tc of the twoor more unit touch sections UTSa, UTSb, and UTSc may be equal to or lessthan the section length of one touch section TS1.

FIG. 23 illustrates two touch sections TS1 and TS2 for the touch mode.Two touch sections TS1 and TS2 are temporally separated from each otherand at least one display section may be present therebetween. Referringto FIG. 23 , similarly to the first touch section TS1, the second touchsection TS2 includes two or more unit touch sections UTSx, UTSy, andUTSz which are continuous.

Touch driving signals TDSx, TDSy, and TDSz output in the two or moreunit touch sections UTSx, UTSy, and UTSz have constant frequencies Fx,Fy, and Fz. The frequency of the touch driving signal output in at leastone unit touch section of the two or more unit touch sections UTSx,UTSy, and UTSz may be different from the frequencies of the touchdriving signals output in the other unit touch sections.

Referring to FIG. 23 , m1 frequencies Fa, Fb, and Fc which aresequentially used in the first touch section TS1 and m2 frequencies Fx,Fy, and Fz which are sequentially used in the second touch section TS2may be equal to each other, or at least one pair thereof may bedifferent from each other. Here, m1 is a natural number equal to orgreater than 2 and equal to or less than the number of unit touchsections k, and m2 is a natural number equal to or greater than 2 andequal to or less than the number of unit touch sections k. Here, m1 andm2 may be equal to each other or may be different from each other. Thatis, when Fa and Fx form a pair, Fb and Fy form a pair, and Fc and Fzform a pair, two frequencies forming each pair may be equal to eachother (Fa=Fx, Fb=Fy, and Fc=Fz). On the other hand, two frequencies ofat least one pair of three pairs may be different from each other. Forexample, Fa=Fx, Fb≠Fy, and Fc=Fz, Fa=Fx, Fb=Fy, and Fc≠Fz, Fa=Fx, Fb≠Fy,and Fc≠Fz, or Fa≠Fx, Fb≠Fy, and Fc≠Fz may be satisfied. According to theabove description, frequencies in different touch sections TS1 and TS2may be modulated variously to achieve an EMI suppression effect.

As illustrated in FIG. 23 , the frequency Fa of the first touch drivingsignal TDSa output in the first unit touch section UTSa of the firsttouch section and the frequency Fx of the touch driving signal TDSxoutput in the first unit touch section UTSx of the second touch sectionTS2 may be equal to each other (Fa=Fx). In this way, by making thefrequencies first used in the touch sections equal to each other, thefrequency can be efficiently modulated in each touch section withrespect to the first-used frequency.

FIG. 24 is a diagram illustrating the touch driving based on multiplefrequencies using the V-sensing method in the touch display device 100according to an embodiment of the present disclosure. FIGS. 25 and 26are diagrams illustrating the touch driving based on multiplefrequencies using the H-sensing method in the touch display device 100according to embodiments of the present disclosure.

Referring to FIGS. 24 and 25 , the display sections DS1 and DS2 for thedisplay mode and the touch sections TS1 and TS2 for the touch mode aretemporally separated from each other. When the V-sensing method is usedto sense a touch as illustrated in FIG. 24 , one frame section includesone display section DS1 and one touch section TS1. When the H-sensingmethod is used to sense a touch as illustrated in FIG. 25 , one framesection includes two or more display sections DS1 and DS2 and one ormore touch sections TS1 and TS2. Even when any of the V-sensing methodand the H-sensing method is used to sense a touch in consideration ofdisplay performance and touch performance, the touch driving methodbased on multiple frequencies for the EMI suppression can be applied.

FIG. 25 illustrates an example in which two display sections DS1 and DS2and two touch sections TS1 and TS2 are allocated to one frame section.FIG. 26 illustrates generalization of such allocation.

Referring to FIG. 26 , each frame section from a first frame section toan m-th frame section includes n touch sections TS1, . . . , TSn. In thefirst frame section, the first touch section TS1 of the n touch sectionsTS1, . . . , TSn may include two or more unit touch section UTSa1,UTSb1, and UTSc1. Here, at least one of frequencies Fa1, Fb1, and Fc1 oftouch driving signals TDSa1, TDSb1, and TDSc1 output in the two or moreunit touch section UTSa1, UTSb1, and UTSa1 may be different from theother ones through a frequency modulating process.

The frequency modulating process can be performed by adjusting sectionlengths Ta1, Tb1, and Tc1 of the two or more unit touch section UTSa1,UTSb1, and UTSc1 or adjusting the numbers of pulses Na1, Nb1, and Nc1 ofthe touch driving signals TDSa1, TDSb1, and TDSc1 output in the two ormore unit touch section UTSa1, UTSb1, and UTSc1. In the first framesection, the n-th touch section TSn of the n touch sections TS1, . . . ,TSn may include two or more unit touch section UTSx1, UTSy1, and UTSz1.Here, at least one of frequencies Fx1, Fy1, and Fz1 of touch drivingsignals TDSx1, TDSy1, and TDSz1 output in the two or more unit touchsection UTSx1, UTSy1, and UTSz1 may be different from the other onesthrough a frequency modulating process.

The frequency modulating process can be performed by adjusting sectionlengths Tx1, Ty1, and Tz1 of the two or more unit touch section UTSx1,UTSy1, and UTSz1 or adjusting the numbers of pulses Nx1, Ny1, and Nz1 ofthe touch driving signals TDSx1, TDSy1, and TDSz1 output in the two ormore unit touch section UTSx1, UTSy1, and UTSz1.

In the m-th frame section, the first touch section TS1 of the n touchsections TS1, . . . , TSn may include two or more unit touch sectionUTSam, UTSbm, and UTScm. Here, at least one of frequencies Fam, Fbm, andFcm of touch driving signals TDSam, TDSbm, and TDScm output in the twoor more unit touch section UTSam, UTSbm, and UTScm may be different fromthe other ones through a frequency modulating process.

The frequency modulating process can be performed by adjusting sectionlengths Tam, Tbm, and Tcm of the two or more unit touch section UTSam,UTSbm, and UTScm or adjusting the numbers of pulses Nam, Nbm, and Ncm ofthe touch driving signals TDSam, TDSbm, and TDScm output in the two ormore unit touch section UTSam, UTSbm, and UTScm.

In the m-th frame section, the n-th touch section TSn of the n touchsections TS1, . . . , TSn may include two or more unit touch sectionUTSxm, UTSym, and UTSzm. Here, at least one of frequencies Fxm, Fym, andFzm of touch driving signals TDSxm, TDSym, and TDSzm output in the twoor more unit touch section UTSxm, UTSym, and UTSzm may be different fromthe other ones through a frequency modulating process.

The frequency modulating process can be performed by adjusting sectionlengths Txm, Tym, and Tzm of the two or more unit touch section UTSxm,UTSym, and UTSzm or adjusting the numbers of pulses Nxm, Nym, and Nzm ofthe touch driving signals TDSxm, TDSym, and TDSzm output in the two ormore unit touch section UTSxm, UTSym, and UTSzm.

FIG. 27 is a diagram illustrating the frequency modulating method forthe touch driving based on multiple frequencies in the touch displaydevice 100 according to an embodiment of the present disclosure.Referring to FIG. 27 , the touch display device 100 according to anembodiment of the present disclosure can perform the touch driving basedon multiple frequencies for sensing a touch and perform a process ofmodulating a frequency of a touch driving signal. For the frequencymodulating process, the touch display device 100 according toembodiments of the present disclosure may further include a frequencytable 2700 that stores available frequencies. The frequency table 2700stores an available frequency list including available frequencies towhich a frequency can be modulated for the frequency modulating process.

The available frequency list stored in the frequency table 2700 may beorganized by touch sections or by unit touch sections. The touch sensingcircuit 120 modulates a frequency of a touch driving signal withreference to the frequency table 2700. Accordingly, the frequencies ofthe touch driving signals output in two or more unit touch sections ofeach touch section may be frequencies extracted from the availablefrequencies stored in the frequency table 2700.

As described above, by setting the available frequency list which can beused for frequency modulation in the frequency table 2700 in advance anddetermining a modulated frequency on the basis of thereof, the touchdisplay device 100 according to an embodiment of the present disclosurecan rapidly perform the frequency modulating process. When thefrequencies of the touch driving signals output in two or more unittouch sections are modulated, the modulated frequencies may besequentially or randomly extracted from the available frequency liststored in the frequency table 2700 for modulation. When the availablefrequencies in the available frequency list stored in the frequencytable 2700 are sequentially selected and used for the frequencymodulating process, the modulated frequencies can be rapidly determined.

For the EMI suppression, the available frequencies in the availablefrequency list should be arranged such that the interval betweenneighboring frequencies in the sequence is equal to or greater than apredetermined interval. When one touch section includes three or moreunit touch sections, the frequencies of the three or more unit touchsections in one touch section can be changed with a constant magnitude.When one frequency of the available frequencies in the availablefrequency list stored in the frequency table 2700 is arbitrarilyselected and used for the frequency modulating process, there is a highpossibility that the arbitrarily selected frequencies will be differentfrom each other, which can help the EMI suppression. As described above,the frequencies modulated in the frequency modulating process using thefrequency table 2700 should be determined to help the EMI suppression.

Accordingly, as illustrated in FIG. 29 which illustrates frequencymodulation characteristics for the touch driving based on multiplefrequencies, m (where m is a natural number equal to or greater than 2,m=3 in this example) frequencies F1, F2, and F3 which are used in onetouch section TS should be extracted from the available frequency liststored in the frequency table 2700 such that the frequency intervals D12and D23 are equal to or greater than a predetermined interval. In orderto enhance the EMI suppression effect, the frequency modulating processshould be performed such that the frequency intervals between the two ormore frequencies F1, F2, and F3 used in one touch section TS aremaximized. In this way, by modulating the frequencies such that thefrequency intervals are maximized with reference to the availablefrequency list stored in advance in the frequency table 2700, it ispossible to remarkably decrease an EMI occurrence possibility and adegree of EMI occurrence.

As another frequency modulating method, the frequency modulating processmay be performed using a frequency hopping technique using a noisemeasurement result. In this regard, the touch sensing circuit 120 canmodulate a frequency of a touch driving signal TDS to a frequency inwhich noise is avoided on the basis of the noise measurement result.Here, the noise measurement result may be information which is outputfrom a noise measuring device mounted inside the touch display device100 and is input to the touch sensing circuit 120 or may be informationwhich is input to the touch display device 100 from an external noisemeasuring device.

A specific method of changing a frequency of a touch driving signal TDSto a noise-avoided frequency will be described below. A noise-inducingfrequency, which is confirmed to be a frequency in which noise isinduced on the basis of the noise measurement result, is removed from apreset available frequency list or a preset available frequency range.Then, when the frequency of the touch driving signal TDS is changed withreference to the available frequency list from which the noise-inducingfrequency is removed or the available frequency range from which thenoise-inducing frequency is removed, a frequency other than thenoise-inducing frequency is selected and set as a modulated frequency ofthe touch driving signal TDS.

On the other hand, the noise-inducing frequency may be removed from theavailable frequency list or the available frequency range for apredetermined time and then may be included therein again, or may beremoved from the available frequency list or the available frequencyrange from a time point at which the noise measurement result isacquired to a time point at which a power supply is turned off and thenmay be included in the available frequency list or the availablefrequency range when the power supply is turned on. Alternatively, thenoise-inducing frequency may be removed from the available frequencylist or the available frequency range and then may be included in theavailable frequency list or the available frequency range again when itis confirmed to be a frequency not inducing noise on the basis of anext-input noise measurement result. On the other hand, the noise can bemeasured by sensing voltages of the touch electrodes TE in the displaypanel 110 in a period (a noise measurement period) other than the touchsensing period (including the touch section).

FIG. 28 is a diagram illustrating another frequency modulating methodfor the touch driving based on multiple frequencies in the touch displaydevice 100 according to an embodiment of the present disclosure.Referring to FIG. 28 , in the frequency modulating process, the touchdisplay device 100 according to the embodiment of the present disclosurecan preset a range of available frequencies (an available frequencyrange) and determine a modulated frequency within the preset availablefrequency range. Accordingly, a frequency of a touch driving signaloutput in each of two or more unit touch sections can be determined inthe preset available frequency range. According to the above-mentionedmethod, by freely determining a modulated frequency within the availablefrequency range, it is possible to enhance randomness of the modulatedfrequency and thus to further enhance the EMI suppression effect.

On the other hand, as illustrated in FIG. 29 , two or more frequenciesF1, F2, and F3 which are used in one touch section TS can be extractedfrom the available frequency range such that the frequency interval isequal to or greater than a predetermined interval. In order to maximizethe EMI suppression effect, a frequency should be selected from theavailable frequency range and be subjected to the frequency modulatingprocess, so as to maximize the frequency interval between the two ormore frequencies F1, F2, and F3 which are used in one touch section TS.In this way, by determining and modulating a frequency in the presetavailable frequency range so as to maximize the frequency interval, itis possible to remarkably decrease an EMI occurrence possibility and adegree of EMI occurrence.

The driving method of the touch display device 100 according to anembodiment of the present disclosure will be described below. FIG. 30 isa flowchart illustrating the driving method of the touch display device100 according to an embodiment of the present disclosure.

Referring to FIG. 30 , the touch display device 100 according to theembodiment of the present disclosure includes a display panel in whichplural data lines and plural gate lines are arranged and plural subpixels defined by the data lines and the gate lines are arranged and hastwo operation modes of a display mode for displaying an image and atouch mode for sensing a touch. Accordingly, a driving method for thesetwo operation modes can be provided.

Referring to FIG. 30 , the driving method of the touch display device100 according to the embodiment of the present disclosure includes adisplay driving step S3010 of driving the data lines and the gate linesin a display section for the display mode and a touch driving step S3020of outputting a touch driving signal of a pulse type for driving atleast one of plural touch electrodes arranged inside or outside thedisplay panel in a touch section for the touch mode. The display drivingstep S3010 and the touch driving step S3020 may be reversed in the orderand may be repeatedly performed. On the other hand, one touch sectionmay include two or more continuous unit touch sections. The touchdriving signals output in the two or more unit touch sections may have aconstant frequency. The frequency of the touch driving signal output inat least one unit touch section of the two or more unit touch sectionsmay be different from the frequency of the touch driving signal outputin the other unit touch sections.

According to the above-mentioned driving method, in the touch driving,at least one of the frequencies of the touch driving signals output fromthe touch electrode in one touch section can be modulated to have adifferent value by performing the touch driving based on multiplefrequencies, whereby an EMI charge share phenomenon occurs and the EMIphenomenon occurring due to the touch driving can be suppressed.

The touch sensing circuit 120 for performing the touch driving based onmultiple frequencies will be described below. FIGS. 31 and 32 arediagrams illustrating the touch sensing circuit 120 of the touch displaydevice 100 according to embodiments of the present disclosure.

Referring to FIGS. 31 and 32 , the touch sensing circuit 120 is acircuit for sensing a touch in the touch display device 100 having twooperation modes including the display mode for displaying an image andthe touch mode for sensing a touch. Referring to FIGS. 31 and 32 , thetouch sensing circuit 120 includes a driving circuit 3110 that outputs atouch driving signal of a pulse type for driving at least one of pluraltouch electrodes TE and a sensing circuit 3120 that detects acapacitance variation in each of the touch electrodes TE to sense atouch or a touch position. The driving circuit 3110 is electricallyconnected to the touch electrodes TE via signal lines SL. Here, thetouch electrodes TE can be connected to the signal lines SL located in adifferent layer via contact holes CNT. The driving circuit 3110 performsthe touch driving based on waveform modulation. Each touch section forthe touch mode may include two or more continuous unit touch sections.The touch driving signals output in the two or more unit touch sectionsmay have a constant frequency. The frequency of the touch driving signaloutput in at least one unit touch section of the two or more unit touchsections may be different from the frequency of the touch driving signaloutput in another unit touch section. It is possible to achieve an EMIsuppression effect by the touch driving based on multiple frequenciesusing the touch sensing circuit 120.

Referring to FIG. 31 , the touch sensing circuit 120 may further includea signal generating circuit 3130 that generates a touch driving signalhaving two or more frequencies through a frequency modulating process.As described above, since only one signal generating circuit 3130 can beused to generate the touch driving signals TDS of frequencies and toperform the multi-frequency driving, it is possible to reduce the numberof signal generating elements.

Referring to FIG. 32 , the touch sensing circuit 120 may further includea signal generating circuit 3130 that generates a touch driving signalof one frequency of two or more frequencies and a signal convertingcircuit 3200 that converts the touch driving signal generated by thesignal generating circuit 3130 into a touch driving signal of anotherfrequency. As described above, since the signal generating circuit 3130generates a touch driving signal of one frequency (a referencefrequency) and the signal converting circuit 3200 generates a touchdriving signal of another frequency to perform the multi-frequencydriving, the number of signal generating elements can increase but theexisting signal generating circuit 3130 using only a single frequencycan be continuously used by adding only the signal converting circuit3200.

The driving circuit 3110, the sensing circuit 3120, the signalgenerating circuit 3130, and the signal converting circuit 3200 can beembodied by separate integrated circuits or separate components. In thiscase, the signal generating circuit 3130 can be embodied by a powerintegrated circuit.

The driving circuit 3110 can be embodied by a read-out IC including amultiplexer, an integrator, an analog-to-digital converter, and thelike, and can output a common voltage to the touch electrodes TE in thedisplay section and output a touch driving signal TDS to the touchelectrodes TE in the touch section. The driving circuit 3110 may beembodied by a combined IC including a functional unit of the read-out ICand a data driving unit for driving the data lines DL. The sensingcircuit 3120 can be embodied by a micro control unit (MCU). The signalconverting circuit 3200 can be embodied by a frequency converter.

On the other hand, two or more of the driving circuit 3110, the sensingcircuit 3120, the signal generating circuit 3130, and the signalconverting circuit 3200 may be embodied to be included in one IC. Forexample, the signal generating circuit 3130 and the driving circuit 3110may be embodied to be included in one IC or one component. For example,the signal generating circuit 3130, the driving circuit 3110, and thesensing circuit 3120 may be embodied to be included in one IC or onecomponent. As described above, by embodying the touch sensing circuit120 using several ICs or components, a touch sensing circuit 120suitable for a middle-size or large-size display device, a small-sizedisplay device, or a mobile device can be embodied.

FIG. 33 is a diagram illustrating the driving circuit 3110 of the touchsensing circuit 120 of the touch display device 100 according to anembodiment of the present disclosure. Referring to FIG. 33 , the drivingcircuit 3110 according to the embodiment of the present disclosureincludes a signal output unit 3310 that outputs a touch driving signalof a pulse type for driving at least one of plural touch electrodes forsensing a touch and a signal detecting unit 3320 that detects a signalfor sensing a touch from the touch electrode supplied with the touchdriving signal.

The signal detected by the signal detecting unit 3320 is transmitted tothe sensing circuit 3120 and is used to sense a touch. The drivingcircuit 3110 is a circuit that performs the touch driving based onmultiple frequencies. Each touch section for the touch mode may includetwo or more continuous unit touch sections. The touch driving signalsoutput in the two or more unit touch sections may have a constantfrequency. The frequency of the touch driving signal output in at leastone unit touch section of the two or more unit touch sections may bedifferent from the frequency of the touch driving signal output inanother unit touch section. It is possible to achieve an EMI suppressioneffect by the touch driving based on multiple frequencies using thetouch sensing circuit 120.

The driving circuit 3110 can include a multiplexer, an integrator, ananalog-to-digital converter, and an analog front end (AFE) and canperform a signal output function and a signal detecting function. Thedriving circuit 3110 can be embodied by a read-out IC. The drivingcircuit 3110 can output a common voltage for the display driving to thetouch electrodes TE in the display section and output a touch drivingsignal TDS to at least one touch electrode TE in the touch section. Thedriving circuit 3110 may be embodied by a combined IC including afunctional unit of the read-out IC and a data driving unit for drivingthe data lines DL.

FIG. 34 is a diagram illustrating an EMI suppression effect of the touchdisplay device 100 according to an embodiment of the present disclosure.Referring to FIG. 34 , when the touch electrodes TE of the touch displaydevice 100 are driven using the touch driving signal TDS having a singlefrequency of 100 KHz, it can be seen that EMI generated in an amplitudemodulation (AM) frequency region (for example, about 500 KHz to about1,605 KHz) is removed by the multi-frequency driving.

FIG. 34 is a graph which is obtained by measuring signal intensity of anEMI signal by frequencies and in which an upper-limit measured value3410 and an average measured value 3420 of EMI signals are arranged byfrequencies. As the measurement result, it can be seen that positions(712 in FIG. 7 , corresponding to EMI) at which the upper-limit measuredvalue 3410 of the EMI signal is greater than a upper-limit referencevalue 711 which is a minimum upper limit value for satisfying an EMIcondition in the AM frequency region are removed.

As the measurement result, it can be seen that positions (722 in FIG. 7, corresponding to EMI) at which the average measured value 3420 of theEMI signals is greater than a reference average value 721 which is aminimum average value for satisfying the EMI condition in the AMfrequency region are removed. That is, the upper-limit measured value3410 and the average measured value 3420 of the EMI signals can satisfythe EMI condition in the AM frequency region through the multi-frequencydriving.

According to the above-mentioned embodiments of the present disclosure,it is possible to provide a driving method, a touch sensing circuit 120,a display panel 110, and a touch display device 100 that can preventelectromagnetic interference (EMI). Accordingly, it is possible toprevent deterioration in system stability, display performance, andtouch sensing performance due to EMI.

According to embodiments of the present disclosure, it is possible toprovide a driving method, a touch sensing circuit 120, a display panel110, and a touch display device 100 that can prevent EMI in a touchsection and prevent unnecessary parasitic capacitance from beinggenerated. According to embodiments of the present disclosure, it ispossible to provide a driving method, a touch sensing circuit 120, adisplay panel 110, and a touch display device 100 that can perform touchdriving using a multi-frequency driving method capable of preventingEMI. Here, the multi-frequency driving method is a touch driving methodusing frequency modulation of a touch driving signal and the frequencymodulation of a touch driving signal can be performed using a techniqueof adjusting a section length of a section (a unit touch section) inwhich a single frequency is used or a technique of adjusting the numberof pulses in a section in which a single frequency is used.

The above description and the accompanying drawings provide an exampleof the technical idea of the present disclosure for illustrativepurposes only. Those skilled in the art will appreciate that variousmodifications and changes such as combinations, separations,substitutions, and changes of configurations are possible withoutdeparting from the essential features of the present disclosure.Therefore, the embodiments disclosed herein are intended to illustrate,not define, the technical idea of the present disclosure, and the scopeof the present disclosure is not limited to the embodiments. The scopeof the present disclosure shall be construed on the basis of theappended claims in such a manner that all the technical ideas within therange equivalent to the claims belong to the scope of the presentdisclosure.

The present disclosure encompasses various modifications to each of theexamples and embodiments discussed herein. According to the disclosure,one or more features described above in one embodiment or example can beequally applied to another embodiment or example described above. Thefeatures of one or more embodiments or examples described above can becombined into each of the embodiments or examples described above. Anyfull or partial combination of one or more embodiment or examples of thedisclosure is also part of the invention.

What is claimed is:
 1. A display device comprising: a display panel; aplurality of touch electrodes; and a touch circuit configured to: supplya first touch driving signal to a first touch electrode in a first touchtime section of a first frame, wherein the first frame includes a firstdisplay time section before the first touch time section, supply asecond touch driving signal to the first touch electrode in a secondtouch time section of a second frame following the first frame, whereinthe second frame includes a second display time section before thesecond touch time section, and supply a third touch driving signal tothe first touch electrode in a third touch time section of a third framefollowing the second frame, wherein the third frame includes a thirddisplay time section before the third touch time section, wherein afrequency of the first touch driving signal supplied to the first touchelectrode is different than a frequency of the second touch drivingsignal or a frequency of the third touch driving signal applied to thefirst touch electrode to reduce an EMI interference.
 2. The displaydevice according to claim 1, wherein the first frame further includes afourth display time section following the first touch time section and afourth touch time section following the fourth display time section,wherein the second frame further includes a fifth display time sectionfollowing the second touch time section and a fifth touch time sectionfollowing the fifth display time section, wherein the third framefurther includes a sixth display time section following the third touchtime section and a sixth touch time section following the sixth displaytime section, and wherein the controller is further configured to:supply a fourth touch driving signal to the first touch electrode in thefourth touch time section of the first frame, supply a fifth touchdriving signal to the first touch electrode in the fifth touch timesection of the second frame, and supply a sixth touch driving signal tothe first touch electrode in the sixth touch time section of the thirdframe.
 3. The display device according to claim 1, wherein the frequencyof the first touch signal is different than a frequency of the fourthtouch driving signal in the first frame, wherein the frequency of thesecond touch driving signal is different than a frequency of the fifthtouch driving signal in the second frame, and wherein the frequency ofthe third touch driving signal is different than a frequency of thesixth touch driving signal in the third frame.
 4. The display deviceaccording to claim 1, wherein the frequency of the first touch drivingsignal is based on a length of the first touch time section and a numberof pulses of the first touch driving signal in the first touch timesection, wherein the frequency of the second touch driving signal isbased on a length of the second touch time section and a number ofpulses of the second touch driving signal in the second touch timesection, and wherein the frequency of the third touch driving signal isbased on a length of the third touch time section and a number of pulsesof the third touch driving signal in the third touch time section. 5.The display device according to claim 1, wherein a length of the firsttouch time section is equal to a length of the second touch timesection, and wherein a number of pulses of the first touch drivingsignal in the first touch time section is different from a number ofpulses of the second touch driving signal in the second touch timesection.
 6. The display device according to claim 1, wherein a length ofthe first touch time section is different from a length of the secondtouch time section, and wherein a number of pulses of the first touchdriving signal in the first touch time section is equal to a number ofpulses of the second touch driving signal in the second touch timesection.
 7. The display device according to claim 1, wherein the displaypanel includes a plurality of data lines and a plurality of gate lines,and wherein the plurality of data lines are configured to receive datavoltages corresponding to an image signal in a display period, and theplurality of gate lines are configured to receive a scan signal in thedisplay period.
 8. The display device according to claim 7, wherein thetouch sensing circuit is further configured to: supply a first load-freedriving signal to all or a part of a group of the data lines whensupplying the first and second touch driving signals.
 9. A method ofcontrolling a display device including a display panel; a plurality oftouch electrodes; and a touch circuit, the method comprising: supplying,via the touch circuit, a first touch driving signal to a first touchelectrode in a first touch time section of a first frame, wherein thefirst frame includes a first display time section before the first touchtime section; supplying, via the touch circuit, a second touch drivingsignal to the first touch electrode in a second touch time section of asecond frame following the first frame, wherein the second frameincludes a second display time section before the second touch timesection; and supplying, via the touch circuit, a third touch drivingsignal to the first touch electrode in a third touch time section of athird frame following the second frame, wherein the third frame includesa third display time section before the third touch time section,wherein a frequency of the first touch driving signal supplied to thefirst touch electrode is different than a frequency of the second touchdriving signal or a frequency of the third touch driving signal appliedto the first touch electrode to reduce an EMI interference.
 10. Themethod according to claim 9, wherein the first frame further includes afourth display time section following the first touch time section and afourth touch time section following the fourth display time section,wherein the second frame further includes a fifth display time sectionfollowing the second touch time section and a fifth touch time sectionfollowing the fifth display time section, wherein the third framefurther includes a sixth display time section following the third touchtime section and a sixth touch time section following the sixth displaytime section, and wherein the method further comprises: supplying, viathe touch circuit, a fourth touch driving signal to the first touchelectrode in the fourth touch time section of the first frame,supplying, via the touch circuit, a fifth touch driving signal to thefirst touch electrode in the fifth touch time section of the secondframe, and supplying, via the touch circuit, a sixth touch drivingsignal to the first touch electrode in the sixth touch time section ofthe third frame.
 11. The method according to claim 9, wherein thefrequency of the first touch signal is different than a frequency of thefourth touch driving signal in the first frame, wherein the frequency ofthe second touch driving signal is different than a frequency of thefifth touch driving signal in the second frame, and wherein thefrequency of the third touch driving signal is different than afrequency of the sixth touch driving signal in the third frame.
 12. Themethod according to claim 9, wherein the frequency of the first touchdriving signal is based on a length of the first touch time section anda number of pulses of the first touch driving signal in the first touchtime section, wherein the frequency of the second touch driving signalis based on a length of the second touch time section and a number ofpulses of the second touch driving signal in the second touch timesection, and wherein the frequency of the third touch driving signal isbased on a length of the third touch time section and a number of pulsesof the third touch driving signal in the third touch time section. 13.The method according to claim 9, wherein a length of the first touchtime section is equal to a length of the second touch time section, andwherein a number of pulses of the first touch driving signal in thefirst touch time section is different from a number of pulses of thesecond touch driving signal in the second touch time section.
 14. Themethod according to claim 9, wherein a length of the first touch timesection is different from a length of the second touch time section, andwherein a number of pulses of the first touch driving signal in thefirst touch time section is equal to a number of pulses of the secondtouch driving signal in the second touch time section.
 15. The methodaccording to claim 9, wherein the display panel includes a plurality ofdata lines and a plurality of gate lines, and wherein the method furthercomprises: applying data voltages to the plurality of data linescorresponding to an image signal in a display period; and applying ascan signal to the plurality of gate lines are in the display period.16. The method according to claim 15, further comprising: supplying, viathe touch circuit, a first load-free driving signal to all or a part ofa group of the data lines when supplying the first and second touchdriving signals.